The parent application is hereby incorporated by reference in its entirety and is directed to a method and system for the in situ removal of radionuclides from a groundwater radionuclide contaminated water source, such as a moving, underground water plume. The parent application provides for a trench or a bed above groundwater level and containing therein, granulated zeolite material, and with the trench having a bottom water barrier lining.
Groundwater containing the radionuclides is distributed, such as by pumping from a water source, generally uniformly, over the top of the zeolite material in the trench, in order to filter the radionuclide contaminated water source through the zeolite bed to remove the radionuclides, or rather metal contaminants, cations, i.e., using the zeolite material, such as by ion exchange with the zeolite material, or more typically by capture of the radionuclides or other contaminates in the internal lattice structure of the zeolite material. The system and method also provides for the discharge of the treated water from the bottom of the trench containing the zeolite material, or recycling all or part of the treated water, as desired, back to the trench for continuous treatment, until the desired level of treatment water is obtained. The system and method also includes for the in situ closure of the trench with the zeolite material, by covering the trench of the zeolite material, for example, with a plastic or clay layer, and subsequently burying the trench with soil to close the bed after the exhaustion of the process by the zeolite material, thereby providing for the in situ treatment and removal of radionuclides or other contaminants from the contaminated water source.
Septic systems are commonly used for the treatment of domestic wastewater, and such septic systems include a septic tank to receive a flowing wastewater effluent or sewerage, typically, from a residence or small business, and which effluent sewerage includes solid matter, and wherein the septic tank bacteria breaks down the sewerage and solid matter. The septic system normally includes one or more leaching fields to receive the continuously flowing treated effluent or "grey water" from the septic tank. Generally, the septic systems are employed in those suburban or farm areas where there is a lack of a central or municipal sewerage facility. Approximately 1/3 of all households in the United States dispose of domestic wastewater through the use of septic tank systems. However, due to poor construction and maintenance or geologic conditions, septic tank systems have polluted underlying ground waters and surface waters, such as streams, rivers, ponds, estuaries and bays.
While septic systems with the septic tank and leach field are acceptable, septic system problems are magnified by the fact that in many areas, particularly rural communities, a substantial reliance on subsurface sewage disposal systems is paralleled by a reliance on private wells for drinking water supplies. These problems, which stem from the nutrient-rich composition of the septic tank effluent water when it reaches the leach field, create hazardous conditions in certain areas. For example, where soils are sandy and well-drained, and on-site groundwater is also a source of drinking water for the domicile, nutrient-rich water from leachate can contaminate the drinking water source. Nutrient-rich leachate from home septic systems can cause unacceptably high nitrate levels in drinking water, resulting in "blue baby" syndrome and other health problems. Nitrogen is a key nutrient of concern because it contributes to the eutrophication of surface water, as well as posing health hazards in groundwater. Nitrates in drinking water, derived from wells where septic system are also present on-site, constitute a widespread, intractable problem throughout the United States. It is therefore desirable to provide for a new and improved septic system and method for the treatment of wastewater effluent and sewerage.